An otoacoustic emission (OAE) is a sound which is generated from within the inner ear. Research indicates that the OAE arises from within the inner ear by a number of different cellular mechanisms. There are two types of otoacoustic emissions: Spontaneous Otoacoustic Emissions (SOAEs) and Evoked Otoacoustic Emissions (EOAEs). SOAEs arise spontaneously and EOAEs require an evoking stimulus.
OAEs are considered to be related to amplification functions of the cochlea; the organ in the ear responsible for hearing. In the absence of external stimulation applied to the cochlea, the activity of the cochlear amplification increases, leading to the production of sound. Research indicates that outer hair cells are the elements that enhance cochlear sensitivity and frequency selectivity in humans.
An otoacoustic emission test (OAE) measures an acoustic response that is produced by the inner ear (cochlea), which in essence reflects back out of the ear in response to a sound stimulus. Generally an audiologist performs the OAE test to determine a strength of the OAE and the sound stimuli that yield the OAE.
The OAE test is usually performed at an audiologist's office or a medical center under controlled conditions at appointed times. A sound probe transmits sound stimuli within the user's ear canal that may be audibly annoying and unpleasant. The results of the OAE test can also differ depending on the user's sound exposure prior to the appointed OAE test time.
A need therefore can be appreciated for evaluating a user's auditory health conveniently over time and with minimal annoyance.